This invention relates to a welding stud having a head portion formed of sheet metal and a shank portion formed of a metal strip which is integral with piece of the sheet metal that forms the head portion. Such welding studs are typically formed with relatively large heads and are specifically useful for fixing heat insulating or sound absorbing mats or other sheets of material to metallic supports. The welding stud usually has a pointed tip which is pressed through the sheet of material into engagement with the metallic support, whereupon the welding process in performed by means of an electrode applied to the surface of the head.
A welding stud of this type is known from U.S. Pat. No. 3,835,285. The known stud is produced from a square blank of sheet metal. For forming the shank portion of the stud, a relatively wide strip is cut free from a corner of the square blank to a point beyond the center thereof and is bent at right angles. The fact that the cuts defining the shank portion extend diagonally with respect to the square head portion results in a relatively long shank. Depending on the thickness of the sheet of material to be fixed, however, the shank may still be too short or, if a larger blank is started from, the head portion may become unnecessarily large.
If a welding stud with a relatively long shank is required, the metal strip punched from the sheet metal blank has a relatively small stiffness. This problem is particularly serious when a welding stud having a relatively small head and a relatively long shank is produced from sheet metal and the metal strip forming the shank is partly cut free from the head portion, but is formed with a small width to avoid undue weakening of the head portion.